Wireless communication technologies have recently been implemented in various manners, such as a wireless Local Area Network (w-LAN) represented by a Wi-Fi technology, Bluetooth, Near Field Communication (NEC), etc., as well as commercialized mobile communication network access. Mobile communication services have evolved from voice call based first-generation mobile communication services into fourth-generation mobile communication networks, thereby making the Internet and multimedia services possible. Next-generation mobile communication services, which will be commercialized in the future, are expected to be provided through an ultra-high frequency band of tens of GHz or more.
Further, with the activation of communication standards, such as a wireless local area network (w-LAN), Bluetooth, etc., electronic devices, for example, mobile communication terminals have been equipped with antenna apparatuses that operate in various different frequency bands. For example, fourth-generation mobile communication services have been operated in a frequency band of 700 MHz, 1.8 GHz, 2.1 GHz, etc., Wi-Fi has been operated in a frequency band of 2.4 GHz and 5 GHz although having a slight difference depending on standards, and Bluetooth has been operated in a frequency band of 2.45 GHz.
In order to provide stable service quality in commercialized wireless communication networks, high gains and a wide range of beam coverage of antenna apparatuses have to be satisfied. Since next-generation mobile communication services will be provided through an ultra-high frequency band of tens of GHz or more, advanced antenna apparatuses that exhibit higher performance than the antenna apparatuses used in the previously commercialized mobile communication services may be required. For example, although a radio signal in a higher frequency band can more rapidly transmit a large amount of information, the radio signal is reflected or interrupted by obstacles due to the straightness thereof and has a short signal arrival distance.
Phased array antennas may be effectively used to raise gains of antenna apparatuses and ensure a wide range of beam coverage. For example, phased array antennas may have a plurality of radiators arranged at a predetermined interval (e.g., half of the wavelength of an operating frequency) and may provide a power supply with a phase difference. Antenna apparatuses for military purposes ensure a wide range of beam coverage by rotating high-gain antennas that form fan beams.